A first-principles study on interfacial properties of Ni(001)/Ni_3Nb(001)  

Ni(001)/Ni_3Nb(001)面界面性质的第一性原理研究(英文)

作　　者：文志勤 赵宇宏[1] 侯华[1] 王楠[1] 傅利[1] 韩培德[2] 

机构地区：[1]中北大学材料科学与工程学院,太原030051 [2]太原理工大学材料科学与工程学院,太原030024

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第5期1500-1505,共6页中国有色金属学报（英文版）

基　　金：Project(2011DFA50520)supported by International Cooperation Project Supported by Ministry of Science and Technology of China;Projects(51204147,51274175)supported by the National Natural Science Foundation of China;Projects(2011-key6,2013-81)supported by Research Project Supported by Shanxi Scholarship Council of China;Projects(2013081017,2012081013)supported by International Cooperation Project Supported by Shanxi Province,China

摘　　要：The Ni （001） surface, Ni3Nb （001） surface and Ni （001）/Ni3Nb （001） interfaces were studied using the first-principles pseudopotential plane-wave method. The adhesion work, thermal stability and electronic structure of Ni/Ni3Nb （001） interfaces were calculated to expound the influence of atom termination and stacking sequence on the interface strength and stability. Simulated results indicate that Ni and Ni3Nb （001） surface models with more than eight atomic layers exhibit bulk-like interior. The （Ni＋Nb）-terminated interface with hollow site stacking has the largest cohesive strength and critical stress for crack propagation and the best thermal stability among the four models. This interfacial Ni and the first nearest neighbor Nb atoms form covalent bonds across the interface region, which are mainly contributed by Nb 4d and Ni 3d valence electrons. By comparison, the thermal stability of Ni/Ni3Nb （001） interfaces is worse than Ni/Ni3A1 （001） interface, implying that the former is harder to form. But the Ni/Ni3Nb interface can improve the mechanical properties ofNi-based superalloys.采用第一性原理赝势平面波的方法研究Ni(001)、Ni3Nb(001)表面和Ni/Ni3Nb(001)界面。计算界面终端为Ni或Ni+Nb,堆积方式为顶部位置或空心位置这4种界面模型的粘附功、稳定性及电子结构。结果表明:Ni(001)和Ni3Nb(001)表面具有8个原子层时展现出较好的体相似性;以Ni+Nb为界面终端,堆积方式为空心位置的界面模型具有最大的结合强度和临界裂纹扩展应力,且具有最好的热稳定性。该模型界面处的Ni原子和Nb原子之间是共价键,这主要是由Nb 4d和Ni 3d轨道的电子贡献的。比较Ni/Ni3Nb(001)界面和Ni/Ni3Al(001)界面的性质可知,前者的热稳定性比后者的差,且更难形成界面,但是Ni/Ni3Nb(001)界面的形成能改善镍基合金的力学性能。

关 键 词：Ni3Nb FIRST-PRINCIPLES INTERFACE electronic structure 

分 类 号：TG146.15[一般工业技术—材料科学与工程]